This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Axonal transport is a process in which membrane bound particles are in transit along microtubules powered by motor proteins belonging to the kinesin and cytoplasmic dynein superfamilies. Recently we identified a Kinesin-3 (KIF1A) that co-purifies with axoplasmic organelles and localizes to organelle/microtubule interfaces. Antibodies raised against Kinesin-3 decorate 100 nm organelles in extruded axoplasm and inhibit organelle transport towards the plus ends of microtubules. These finding suggest that Kinesin-3 may be responsible for moving 100 nm organelles towards the plus ends of microtubules. Here, we propose to characterize the motor properties of purified Kinesin-3 and to identify the molecular anatomy of the Kinesin-3 cargo. Understanding the rate and direction of Kinesin-3 movement and the molecular composition of its cargo will help establish Kinesin-3's role in the axon and determine its contribution to motor mediated transport.